Foldable and portable vehicle

ABSTRACT

A foldable, portable bicycle in which the handlebar, its elongated post, the seat assembly, the pedal crank and the frame are foldable quickly and easily into a compact and regular-shaped package that is easily portable and storable, and are unfoldable with similar speed and ease into a safe, durable and comfortable bicycle that accommodates adults of normal size. The frame is designed with a low profile that is substantially the same in height and thickness as the dimensions of the wheels and their supports, and the handlebar and seat assemblies extend upwardly to normal height, but fold and collapse in novel ways, along with the pedals, to substantially within the confines outlined by the folded frame. 
     Unique quick-release latches are provided for the handlebar post, the seat post sections, the frame hinge and the pedal hinges, and the pedal cranks are specially designed for effective performance and easy, compact folding. Optional features include an enclosed front carrying compartment, a bracing cable permitting the seat post to be made of lighter materials, a rear carrying rack that extends the flat and low profile across the rear frame section, and a shopping cart mode in which the partially folded frame is held with the two bicycle wheels parallel, and an auxiliary wheel assembly stored in the mid-portion of the frame is swung out to form a 3-wheel cart with a carrying deck. Numerous additional detailed features are included in the disclosure.

This is a division of application Ser. No. 233,624, filed Feb. 12, 1981,U.S. Pat. No. 4,433,852.

BACKGROUND OF THE INVENTION

This invention relates to foldable vehicles, and has particularreference to a bicycle that is capable of being reduced to a folded,portable package that can be carried by the user and stored in arelatively small space. Included in the broad category of vehicles towhich the invention relates are collapsible and so-called "knock-down"vehicles, and vehicles which may be motor driven as well as driven bypedal-and-sprocket drives, and particularly motorized bicycles of thetype known as mopeds.

For many years, efforts have been made to provide a practical foldableand portable bicycle for use in travel to and from bus stops, trainstations, and the like, and to and from offices, grocery markets andother places of business, as well as for other typically short tripsthat can conveniently be made by bicycle, except for the problem ofstorage of the bicycle during travel on another vehicle, or duringshopping, work, or other activity at the traveller's destination. Bothconvenience of travel and energy-saving economy are important motivatingfactors in this respect, and with the current increases in the cost ofother forms of travel, and particularly in the cost of gasoline, thesefactors have become even more important than in the past.

The general objective in this field is to enable the cyclist to fold andcollapse the bicycle quickly and easily into a compact and lightweightpackage that can be carried by the cyclist onto another vehicle, or intoan office or shop, and stowed in available space such as under a seat,in a locker, or in some other relatively small space. Of course, it isalso important for the cyclist to be able to unfold the bicycle andprepare it quickly and easily for use, and for the bicycle to performsatisfactorily in the unfolded condition, in terms of riding ease andcomfort, safety, durability and other operating characteristics. Inaddition, it is important that the bicycle can be mass-produced atreasonable cost.

Many prior bicycles have been proposed in this general field, alldesigned to attempt to fulfill the need for a practical folding bicycle.One such bicycle is shown in this inventor's U.S. Pat. No. 4,067,589.Each of these bicycles, however, has shortcomings that prevent it frombeing the optimum bicycle of this type.

In the prior bicycles, including the one disclosed in the foregoingpatent, the main components of the bicycle that can be folded andcollapsed are the frame, the handlebar and steering assembly, the seatassembly, and in some cases the drive assembly, including thesprocket/pedal assembly. The wheels of the bicycle constitute theprincipal components that cannot practically be reduced in size, andthus typically are made relatively small as compared to conventionaladult bicycles. To adapt a small-wheeled bicycle for use by an adult,the handlebar and steering assembly and the seat assembly extend upwardto a conventional height. Except for the effect on "ride" on a roughsurface, the relative disadvantages of the small wheels are notsignificant when the bicycle is equipped with a drive assembly providinga high front-to rear drive ratio.

The available foldable and collapsible bicycles suffer from a number ofdeficiencies, including inconvenient and time-consuming complexity inthe folding and unfolding operations, excessive weight that is requiredin some designs for safe and durable construction, less-than-adequaterigidity for safe operation with other designs, and relative bulkinessor awkward shape in the folded condition with most designs.

The objective of the present invention is to provide a foldable andportable bicycle in which these characteristics are optimized so thatthe bicycle is quicker and easier to fold and unfold, is light in weightyet sturdy, durable and safe for normal operation, and is more compact,tightly folded and held, and convenient to handle in the foldedcondition for greater ease of storage and carrying, and as optionalbenefits, also has convenient storage elements for use during riding andis capable of being rolled as a cart both in the folded condition and ina partially folded condition in which the bicycle can be used to carrymerchandise such as groceries. In addition, important objectives are toprovide such a bicycle that can be mass-produced using conventionalproduction technology to sell at a competitive price, and also can beadjusted to or provided in a full range of different ridingconfigurations with respect to handlebar and seat positions, drive ratioand the like.

SUMMARY OF THE INVENTION

The present invention resides in the novel construction and interactionof the handlebar and steering assembly, the frame, and thesprocket/pedal assembly, preferably with an improved seat assembly ofthe general type shown in this inventor's prior patent, to produce apractical foldable and portable bicycle that more effectivelyaccomplishes the objectives of such a bicycle in speed and convenienceof folding and unfolding, compactness, weight, cost and operationalcharacteristics. The bicycle has a low-profile folding frame that issubstantially the same in height and thickness as the dimensions of thewheels and their supports, yet can maintain the basic "diamond"construction that is preferred for conventional bicycles, and all of theelements of the bicycle fold and collapse into the folded frame in novelways, to lie, and be held, substantially within the confines of thefolded frame, and also to open quickly and easily into, and be latchedsecurely in, the normal operating condition.

More specifically, as illustrated by the presently preferred embodimentsshown herein, the bicycle of the invention has an improved handlebar andsteering assembly with a multi-section, longitudinally collapsiblesteering post which is hinged above a vertically compact steeringbearing to fold into a position alongside the front wheel, about a hingeaxis that is positioned to offset the steering post laterally from thewheel as an incident to the swinging of the post to the folded position,the handlebar also being turned from its normally transverse positioninto a generally front to rear position during folding, as a result ofthe hinge angle in the preferred embodiment. The handlebar is ofrelatively flat construction to lie compactly alongside the front wheel,and the combination of the longitudinally collapsible post, thevertically compact bearing, the hinge, and the flat handlebar makes itpossible to reduce the height of the front portion of the bicycle in aquick and simple operation to only slightly more than the diameter ofthe wheel. Novel quick-release latch means effect secure locking of thepost in the operating condition, and also contribute to the ease offolding, with easily accessible and operable but unobtrusive manualactuators, and the post also is designed to be positioned quickly andeasily in selected angular and longitudinally extended positions.

The frame of the novel bicycle has generally triangular front and rearsections that are joined together by a hinge that is midway between thefront and rear axles and connects the sections for swinging about anupright axis into a folded condition in which the sections are inside-by-side relation with the folded steering assembly preferablystored compactly between them. The upper extremities of both framesections lie along or below an imaginary reference line that isimmediately beneath the level of the vertically compact front steeringbearing, and in a preferred embodiment, the upper sides of the sectionsare elongated flat sides lying along and generally defining thisreference line, formed by a front "deck" on the front section and a rearcarrying rack on the rear section.

While the specific frame construction may be varied, the presentlypreferred embodiment comprises generally triangular sections (apart fromthe carrying rack) having upright flat sides that abut against eachother along the mid-frame hinge axis, the rear section taperingrearwardly to a rear wheel mount at axle level and the front sectiontapering forwardly to the front steering bearing that is spaced aboveaxle level by an amount slightly greater than the radius of the frontwheel. Both sections preferably are of an open frame or box-likeconstruction, and are constructed of elongated tubular struts for highstrength and light weight in the triangular construction. In oneembodiment, the front section is enclosed in sheet material to provide astorage compartment, or is formed entirely of sheet material in anenclosed box-like form which provides suitable structural strengthwithout reinforcing struts, while providing a convenient storagecompartment. In all embodiments, the uppermost components of the frame,including the rear carrying rack, lie along and define a flat andgenerally horizontal upper extremity immediately above the level of thewheels, and the sides of the frame, when folded and when unfolded, aregenerally flat and without protruding parts, for a compact and easilyhandled package.

To reduce the overall length of the folded front section, the frontwheel support, which normally is inclined forwardly at a conventionalangle and has a conventional forward bend or "offset" at its lower end,is reversible, by rotation of the entire handlebar and steering assemblythrough one hundred and eighty degrees, reversing the offset anddisposing the front side of the wheel beneath the front frame section,with the reversed rear side of the wheel closer to the rear to shortenthe overall length by an amount determined by the amount of offset.Detent means are provided for latching the support snugly to the frameto fix the angular position of these parts during and after folding.

With front and rear frame sections having flat abutting sides, themid-frame hinge is formed along one upright edge of a flat side and aselectively operable mid-frame latch is formed along the oppositeupright edge to hold the frame securely but releasably in the unfoldedoperating condition. The preferred hinge construction is an elongatedpin-and-sleeve combination on one side, and the preferred latch couplesthe front and rear sections on the other side, at least along the lowerside of the frame, and has an easily accessible and operable butunobtrusive manual operator. With this frame and hinge arrangement, theforces acting on the frame during normal operation tend to close thejoint at the top of the frame and reduce the forces acting on the latchat the top. The latch preferably has an upper latching component that isoperated with the lower latching component for increased latchingsecurity.

The improved seat assembly is generally similar to the collapsible seatstructure of this inventor's prior patent, with a multiple-sectiontelescoping seat post, predetermination of extended and angularpositions, and quick and easy movement of the seat from a collapsedposition adjacent the upper reference line of the frame to an extendedposition at the proper height for the cyclist. The telescoping postsections are of a non-circular cross-section that is oriented to provideoptimum firmness of fit under the weight of a cyclist, and improved andsimplified quick-operating latches are provided for the multiple-sectionpost. When the seat assembly is partially collapsed, it serves as aconvenient handle for towing or pushing the folded bicycle in an uprightposition.

To reduce the usual sprocket/pedal assembly to a more compact form, thetwo pedals are supported in their normal laterally outwardly projectingpositions on two generally radial cranks that have inner end portionsthat are pivotally mounted on the opposite ends of an axle for thesprocket, and are latched for quick and easy release and swinging intolaterally inwardly projecting folded positions in which the pedals tuckinto the folded frame and are nested and latched in the frame. Each ofthe cranks has an inner end portion that extends across the sprocketaxis and interfits with a drive connector on the axle having drivingabutments that are normally engaged with opposed abutments on the crank,and a pivot is provided at the inner end between the crank and the driveconnector so that the crank is elongated as it swings from its normalposition to an oppositely extending position in which the pedal projectsinwardly rather than outwardly.

In addition, the outer end portions of the cranks are disposed at angleswith the inner end portions, and thus are angularly offset from trueradial positions, to swing into compact folding positions other thanpositions that are directly opposite (that is, 180 degrees away from)the normal positions. Preferably, the outer end portion of at least thecrank that lies alongside the sprocket also is inclined laterallyoutwardly away from the sprocket, as well as angularly from a trueradial position. The outward incline positions the pedal conventionally,with normal operating clearance, and, when reversed during folding,positions the crank closer to the sprocket for folded compactness. Alateral offset is provided for the other crank, for similar foldedcompactness.

Latching of the pedals into the frame is accomplished most simply byengaging the pedals with an interference fit over elements of the rearframe section, using the inherent resilience of the structures to permitlatching engagement and disengagement. The pedals and the engagingelements are spaced so that upon reversal of the cranks, thenow-inwardly extending pedals pass across and abut against a frameelement, preferably a lower strut of the rear section on one side and anupper strut on the other. Unobtrusive quick-release latches areconveniently actuatable as an incident to grasping of the cranks to movethem to their folded positions, and relatch with an effective snapaction as an incident to the return of the cranks to their normalpositions.

These novel assemblies make it possible to produce a lightweightfoldable bicycle that is highly effective for its intended purposes, forexample, using preferred sixteen-inch wheels and weighing on the orderof twenty to twenty-four pounds, capable of being folded or unfolded inten to fifteen seconds, to and from a size that will fit convenientlyunder a bus seat or in a locker, with all of the normally protrudingcomponents folded, tucked and securely held in the folded frame. Ofcourse, wheels of other sizes may be used, and the features of theinvention will apply to produce an optimum folded bicycle with a givenwheel size.

Accordingly, the folded bicycle forms a tight, generally flat-sidedpackage without objectionable protruding or loose parts, with the twowheels side by side at one end of the package and the adjacent ends ofthe frame sections side by side at the opposite end of the package. Thispermits convenient rolling of the folded bicycle on the wheels, usingthe hinged frame struts or the seat as a handle, and also makes itpossible to stand the package in an upright position on the wheels, thewheel fenders having ends that are especially positioned to provide afour-point base.

More detailed features include the novel design of the preferred latchesfor the steering post hinge and the frame, with actuators that operatequickly and easily during both latching and unlatching, hold the latchedcomponents very securely when in the latched condition. Similarly, thelatches for the telescoping sections of the steering post and the seatposts are of novel designs for secure latching, ease of operation, andunobtrusive positioning on the bicycle. All of the latches are incompact, unobtrusive and tightly held positions both when latched andwhen unlatched.

Additional optional features include a special seat-bracing cable forreinforcing the seat structure for heavy riders, and permitting the useof lighter materials for the seat post, the cable being attached at oneend to the seat assembly above the frame and extending forwardly to thefront end portion of the frame. The cable preferably extends into thefront section and then reversely to the mid-frame hinge, where it iswrapped around separable portions of the two frame sections to reinforcethe frame in use and to be taken up to some extent as the frame isfolded. The other cables typically provided for conventionalaccessories, including brakes and a gear selector, are positioned to befolded with the bicycle into securely held and unobtrusive positions, inall embodiments.

Another optional feature is the provision of an auxiliary wheel assemblythat is extendable from the folded frame to convert the bicycle into athree-wheeled shopping cart, with the seat on the handlebar serving as atowing handle, and the front deck and the rear carrying rack providing acarrying surface for bags and parcels. The detent means for holding theframe in tightly folded condition include a second set of detents forholding the front wheel parallel to the rear wheel when the frame is ina spread, shallow "V" configuration, with a pedal crank unfolded betweenthem to hold them partially apart. An elastic tie draws them toward eachother and against the pedal crank. The auxiliary wheel also provides aconvenient three-wheel support for rolling the fully folded bicycle,using the partially extended seat as a handle.

In an alternative embodiment of the steering post and its hinge, asteering post extension section is rotatable in a base section toaccomplish the turning of the handlebar into a front-to-rear positionduring folding, and the steering post hinge is positioned along onelateral side of the post to offset the post to one side of the wheelwithout turning of the handlebar by the hinge. Detent means are providedfor latching the extension section in different angular positions fornormal operation and for folding, and also in different extendedpositions. A novel quick-release clamp holds the rotatable extensionsection securely in its selected position. This embodiment provides analternative to the preferred embodiment, accomplishing the turning ofthe handlebar in a less direct fashion.

Other detailed features and advantages of the invention will becomeapparent from the accompanying drawings, taken in conjunction with thedetailed description of the presently preferred embodiments of theinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a foldable and portable bicycleembodying the novel features of the present invention, shown in theunfolded operating condition with a rear carrying rack which is apreferred optional feature of the invention;

FIG. 2 is a perspective view similar to FIG. 1 but taken from theopposite side of the bicycle;

FIG. 3 is a perspective view of the bicycle of FIGS. 1 and 2, shown on aslightly enlarged scale in the folded condition of the bicycle;

FIG. 4 is a schematic side elevational view of the bicycle of FIGS. 1and 2, shown in the unfolded, operational condition with structuralelements simplified and removed for clarity of illustration;

FIG. 5 is a view similar to FIG. 4 illustrating initial steps infolding--collapsing the front post, reversing the steering assembly, andfolding the pedal cranks;

FIG. 6 is a view similar to FIG. 5 illustrating further steps infolding--folding over the steering post and handlebar, and collapsingthe seat structure;

FIG. 7 is a view similar to FIG. 6 illustrating a further step infolding--swinging the two frame sections into side-by-side relation;

FIG. 8 is a view similar to FIG. 7 showing the folded bicycle tiltedinto a standing position;

FIG. 9 is a view similar to FIG. 8 showing the folded bicycle in apushing or towing position;

FIG. 10 is a fragmentary side elevational view of part of the frontportion of the bicycle of FIGS. 1 and 2, on an enlarged scale, with someparts removed and with the reversed position of the steering assemblyindicated in broken lines;

FIG. 11 is a cross-sectional and elevational view taken generally alongline 11--11 of FIG. 10;

FIG. 12 (on sheet 6 of the drawings) is a fragmentary cross-sectionalview taken generally along line 12--12 of FIG. 10, with some parts shownin side elevation;

FIG. 13 is an enlarged cross-sectional view taken along line 13--13 ofFIG. 12;

FIG. 14 (on sheet 4 of the drawings) is a fragmentary cross-sectionalview taken generally along line 14--14 of FIG. 10;

FIG. 15 is a fragmentary cross-section similar to FIG. 14 but showingthe front wheel in the reversed position;

FIG. 16 (sheet 2 of the drawings) is an enlarged fragmentary sideelevation taken generally within the arc 16 of FIG. 10, with a detentpin shown in full in a normal position and in broken lines in a reversedposition;

FIG. 17 is a fragmentary cross-section taken generally along line 17--17of FIG. 16 with the detent pin in the reversed position;

FIG. 18 (sheet 5 of the drawings) is an enlarged fragmentarycross-sectional view taken substantially along line 18--18 of FIG. 15;

FIG. 19 is a view similar to FIG. 18 with the handlebar and steeringpost folded over, and showing details of the front hinge latch in theunlatched condition;

FIG. 20 is an enlarged fragmentary cross-sectional view takensubstantially along line 20--20 of FIG. 15, shown partly in sideelevation, and with an intermediate condition of the front hinge latchshown in broken lines;

FIG. 21 is an enlarged fragmentary cross-sectional view taken generallyalong line 21--21 of FIG. 19, and shown partly in side elevation;

FIG. 22 is an enlarged fragmentary cross-sectional view taken throughthe steering bearing generally along line 22--22 of FIG. 20 and shown inmodified form with added wheel-alignment elements;

FIG. 23 is an isolated and exploded perspective view, on a reducedscale, of the wheel-alignment elements, one element being shown with aportion of the sidewall broken away;

FIG. 24 is a view similar to FIG. 22 showing an alternative embodimentof the steering bearing;

FIG. 25 is an enlarged fragmentary side elevational view of themid-frame area in FIG. 1, with the folded position of one crank andpedal shown in broken lines;

FIG. 26 is an enlarged fragmentary cross-sectional view taken along line26--26 of FIG. 25;

FIG. 27 is an enlarged fragmentary perspective view of parts of FIG. 26,taken in the direction of the arrow 27 therein and partly incross-section, showing a seat post latch in the released condition;

FIG. 28 is a further enlarged fragmentary view taken generally alongline 28--28 of FIG. 25 with some parts shown in cross-section and withthe folded positions of the cranks and pedals shown in broken lines;

FIG. 29 is a view similar to FIG. 25 but taken from the opposite side ofthe mid-frame area, the side shown in FIG. 2, and showing the foldedcondition of the crank on the other side in broken lines;

FIG. 30 is a fragmentary cross-sectional view taken generally along line30--30 of FIG. 25;

FIG. 31 is a fragmentary cross-sectional view taken generally along line31--31 of FIG. 30;

FIG. 32 is a fragmentary view of parts in FIG. 30, but after themid-frame latch has been released and the frame has been folded;

FIG. 33 is a perspective view similar to FIG. 1 but showing analternative embodiment in which the front frame section is an enclosedcompartment and including a bracing cable for the seat;

FIG. 34 is an enlarged fragmentary cross-sectional view takensubstantially along line 34--34 of FIG. 33;

FIG. 35 is an enlarged fragmentary cross-sectional view takensubstantially along line 35--35 of FIG. 34;

FIG. 36 is a cross-sectional view of the bicycle of FIG. 33 in apartially folded shopping cart mode, taken in a horizontal plane abovethe rear carrying rack and the front deck, generally along line 36--36of FIG. 38, with an elastic tie and auxiliary wheel assembly added, andwith the bracing cable removed;

FIG. 37 is a fragmentary cross-sectional view on an enlarged scale takensubstantially along line 37--37 of FIG. 36;

FIG. 38 is a fragmentary elevational view taken in the direction of thearrows 38 in FIG. 37.

FIG. 39 is a view similar to FIG. 18 showing an alternative embodimentof the steering post and hinge, with a folding position of the handlebarshown in broken lines;

FIG. 40 is a view similar to FIG. 19 showing a portion of thealternative embodiment of FIG. 39, with the steering post folded over;

FIG. 41 is an enlarged fragmentary cross-sectional view takensubstantially along line 41--41 of FIG. 39, with the steering postlongitudinally collapsed and in the normal operating position;

FIG. 42 is an enlarged fragmentary cross-sectional view takensubstantially along line 42--42 of FIG. 39; and

FIG. 43 (sheet 2 of the drawings) is an enlarged fragmentary explodedperspective view of portions of the frame and the steering post, withcatch means thereon.

DETAILED DESCRIPTION OF THE FIRST EMBODIMENT

As shown in the drawings for purposes of illustration, the invention isembodied in a foldable and portable bicycle, indicated generally by thereference number 10, of the type that is adapted to be reduced to acompact package, as shown in FIG. 3, for ease of carrying and storage.Bicycles of this general type are useful in riding to and from modes ofpublic transportation, such as buses and trains on which the foldedbicycle can be carried or stowed in available space during the ride, andalso in riding to and from commercial establishments and places ofemployment, where the bicycle also can be folded, carried into abuilding, and stored until needed for the return trip.

As can be seen in FIGS. 1 and 2, the bicycle 10 comprises, in general,the usual main components and assemblies including front and rear wheels11 and 12, a frame indicated generally by the reference number 13, aseat assembly 14 mounted in the mid-portion of the frame, a driveassembly including front and rear sprockets 15 and 16, sometimes called"chainwheels", connected by an endless chain 17 to drive the rear wheel12 about a rear axle 18 as the front sprocket is turned by two pedals19, and a handlebar and steering assembly for turning the front wheel11. This assembly includes a front wheel support of the usual "fork"type having two depending prongs 20 that are disposed on opposite sidesof the wheel and have spaced lower ends forming a front wheel "drop-out"in which a front axle 21 is mounted. The upper end or "crown" 22 of thefork is rotatably connected through a wheel mount or "headtude" 23 to apost 24 for the handlebar 25, the wheel mount corresponding in functionto the "headtube" of a conventional bicycle.

Optional components that preferably are included as conventional anduseful elements of a bicycle are a carrying rack 26 above the rearwheel, arcuate front and rear fenders 27 and 28 which are mounted on theframe 13 to overlie the front and rear wheels 11 and 12, and front andrear caliper brake mechanisms 29 and 30 on the front of the fork crown22 and on the frame above the rear wheel, having lever-supported brakepads 31 for frictionally clamping the sides of the wheels. The brakemechanisms are actuated by hand levers 32 and 33 supported near theopposite ends of the handlebar 25 and connected to the brake mechanismsby cables 34 and 35, the rear brake cable being routed along the frameand fastened thereto by a clip 35a (FIG. 2). Also provided in theillustrative bicycle 10, for ease of pedaling under a variety ofconditions, is a multi-speed transmission (not shown in detail) with amanual gear selector 37 that is mounted on the handlebar and connectedto the transmission by a cable 38. Other conventional bicycleaccessories (not shown) also may be added, as desired.

It has been proposed in the past to fold bicycles of the foregoinggeneral character, as shown by the aforementioned patent, includingfolding and collapsing of the frame, the steering assembly, the seatassembly and the pedals in various ways and combinations that reduce thefolded size of the bicycle with varying degrees of success. Thisinvention contemplates, in its broader aspects, an improved foldablebicycle which, as a result of the novel construction of a foldinghandlebar and steering assembly and its interaction with a novel foldingframe, augmented by improved collapsible seat assembly and foldingsprocket/pedal assembly, optimizes the advantages and convenience of thebicycle. The advantages and convenience are enhanced by special latchesfor quick and easy operation in both latching and unlatching, and byother more detailed aspects of the invention.

The improved handlebar and steering assembly has a muliple section,longitudinally collapsible steering post 24 that is extendable to alength greater than the front wheel diameter and collapsible to a lengthapproximately the same as the wheel diameter, and this post is hinged onthe front wheel mount 23 to fold about a hinge axis 39 that is locatedimmediately above the front wheel 11, into a position alongside thefront wheel while turning the handlebar 25 from its normal transverseposition (FIGS. 1, 2 and 4) into a generally front-to-rear position(FIGS. 6 and 19) alongside the wheel. The handlebar is relatively flatin shape with a relatively small amount of front-to-rear displacement inits normal operating position, and thus lies relatively flatly againstthe wheel when folded, for eventual compact positioning within thefolded frame 13. Thus, all of the steering structure above the frontwheel mount is disposed beside the wheel, and the front wheel mount, anda steering bearing 40 therein, are made vertically compact to reduce theheight of the folded front portion of the bicycle virtually to thediameter of the front wheel.

More specifically, the steering post 24 comprises a base section 24awhich preferably is relatively broad adjacent its lower end and tapersupwardly, and an extension section 24b that telescopes with the basesection and extends upwardly to the handlebar 25, which is secured tothe extension section substantially perpendicular to it, for example, bywelding. The two sections of the post are non-circular in cross-section,herein square, to hold the sections slidably in a fixed angularrelationship. On the lower end of the base section is a mounting element41, herein a flanged transverse base plate.

To hold the post 24 with its two sections 24a and 24b in a selectedextended position, a novel quick-release clamp 42 (see FIGS. 12 and 13)is provided around the upper end of the base section 24a, to lock thesections together. For this purpose, the upper end portion of the basesection is made flexible on one side by a pair of longitudinal slots 43(FIG. 13), and the illustrative clamp comprises a collar 44 that isdisposed around the upper end of the base section with a screw 45 thatis threaded through the collar and abuts against the flexible upper endportion of the base section, preferably with a wide bearing pad 46 onits inner end pressing against the flexible side of the base section. Onthe outer end of the screw 45 is an actuator in the form of a lever 47for tightening the screw against the base section, and thus constrictingthe flexible upper end portion around the extension section 24b. Thelever should be maintained in an out-of-the way position when the clampis tightened, preferably depending along one side as shown in FIG. 1,and to insure that such positioning can be maintained, despitevariations that occur in use, the lever is connected to the screw 45 bya splined and outwardly tapered head 45a, and a screw fastener 48 thatis threaded into the head through the lever to press a tapered andsplined socket or seat therein tightly onto the splined head in aselectively adjustable angular position.

Rapid location of the post 24 in a selected extended position duringunfolding is facilitated by an adjustable limiting device shown in FIG.12, in the form of a flexible cable 49 that is anchored at one end onthe base section 24a and attached at the other end to the extensionsection 24b. As shown in FIG. 12, the lower end of the cable herein isattached to the base plate 41 by a lower anchor screw 50 and extendsupwardly through a hole in the plate, and the upper end portion extendsupwardly through the extension section 24b and is secured to an upperanchor screw 52 that is threaded into the side of the extension sectionabove the base section. The length of cable between the upper and loweranchor screws is adjustable to select an extended length for the post24, and the upper anchor screw forms a stop for abutting against theupper end of the base section and limiting the longitudinal telescopingof the extension section into the base section, thus determining thecollapsed length of the post. A stop washer 53 preferably is provided onthe upper anchor screw for engagement with the base section.

As can be seen in FIGS. 1 and 2, the illustrative handlebar 25 isgenerally in the shape of a shallow inverted "V", having a central apexto which the extension section 24b is welded and opposite end portions25a and 25b forming hand grips to be grasped by the rider. These endportions are inclined somewhat downwardly and to the rear from the apex,but it is important for optimum compactness to limit the amount offront-to-rear displacement of the handlebars. The downward and rearwardincline shown herein provides a comfortable angle for the cyclist, andalso provides clearance in the folded bicycle for accommodating thebrake actuators 32 and 33.

The height of the handlebar in the unfolded condition is a matter ofpersonal preference, and is adjustable over a wide range, theillustrative handlebar being adjustable to almost twice the length ofthe base section 24a of the post. It can be seen in FIG. 12, however,that the extension section can be made even longer, for a greatermaximum length. The length illustrated in FIGS. 1, 2 and 12 positionsthe handlebar in a relatively low, "racing" position preferred by manycyclists, requiring no further collapse during folding of the bicycle. Agreater extended length, shown in FIG. 4, is preferred by others, forriding in a more erect position, from which the handlebar should belowered as a first step as the bicycle is being folded. With the quickrelease latch shown herein, this requires only a second or two in thefolding and unfolding operations.

The handlebar and steering assembly are supported on the front end ofthe frame 13 on the wheel mount 23 which has an arcuate sidewall 23athat surrounds the steering bearing 40 of the bicycle. The hinge axis 39for the steering post 24 is defined by a hinge pin 54 that connects thebase plate 41 to a cup-like hinge base 55 (see FIGS. 18 through 24) thatis connected through the bearing to the crown 22 of front wheel fork 20.The hinge pin 54 is disposed on one side of the hinge base, and extendsthrough interfitting and overlapping wings 57 and 58 on correspondingsides of the two bases, with a head on each end holding the pin in placeso that the base plate of the steering post 24 is swingable about thehinge axis 39 defined by the pin 54 between the operating position shownin FIG. 18 and the folded position shown in FIG. 19.

With the hinge axis 39 offset to one side of the post 24, the post istransferred during folding from its normal position in which it islaterally centered over the front wheel mount 23 and the wheel 11, to alaterally offset position generally in a plane that lies alongside thewheel. In addition, the location and attitude of the post hinge canserve to offset the post longitudinally from the fork prongs 20, to liecloser to the side of the wheel, and also can serve to turn thehandlebar from its normal laterally projecting position to a generallyfront-to-rear position as an incident to the folding. This turningfunction is included in the preferred embodiments of the invention, butit is to be noted that the extension section 24b of the post can be maderotatable in the base section 24a, adding another clamping andpositioning operation to the unfolding procedure.

In the preferred embodiment, the hinge pin 54 is inclined at an angle ofapproximately forty-five degrees relative to the plane of the wheel toextend obliquely across the base of the post, from one lateral side tothe front side (see FIG. 14) and also is tilted upwardly toward thefront, at an angle of about 15 to 20 degrees from horizontal (see FIG.2). The opposed edges of the base plate 41 and the hinge base 55preferably lie along an inclined plane that includes the tilted hingeaxis 39, the base plate being inclined to converge slightly toward thehinge base as shown in FIG. 20. The compound angle of the hinge axis 39results in tilting of the post 24 during folding, toward the frontportion of the front wheel and beyond the depending prong 20 of thefork, while turning the handlebar generally into a front-to-rearattitude in a vertical plane alongside the wheel.

As shown schematically in FIGS. 5, 6 and 15, it is preferred to turn thewheel one hundred and eighty degrees to a folding position beforefolding the post and handlebars, to reduce the overall length beforefolding, the fork having a conventional forward bend or "offset" nearits lower end which offsets the wheel to the front. This offset isreversed when the wheel is reversed, thus saving the amount of theoffset in the length of the bicycle. Reversal of the wheel may beeliminated, in which case the location and angle of the hinge should beadjusted to the different circumstances, which also affect the locationof the mid-frame hinge.

In this instance, provision is made for limiting the turning of thesteering assembly to a folding position that is approximately onehundred and eighty degrees from the forward position, and detaining thesteering assembly releasably in this position to avoid looseness whenthe frame 13 is folded and to assume a parallel relationship with therear wheel for easy pushing or towing. For this purpose, interactingdetent means are provided on the crown 22 of the fork and on thenon-rotating wheel mount 23, to be releasably engaged when the steeringassembly reaches the reversed position for folding. As shown in FIGS. 16and 17, these means include a normally forwardly projecting pin 59 onthe front side of the crown, and a flexible detent strap 60 fastened bya screw 61 to the underside of the wheel mount 23, in the path of thepin during turning of the wheel. The strap is positioned to engage thepin as it reaches the right end (FIG. 17), and is yieldable upwardlyunder the camming action of the pin and the curved end 60a of the strap,to permit the pin to pass along the strap to a detent notch 62 in whichthe pin is seated when the steering assembly is reversed. A resilientpad 64 confined between the strap and the wheel mount provides forresilient yielding of the strap.

Although the prongs 22 of the wheel supporting fork are inclineddownwardly and forwardly at a conventional angle from the wheel mount23, the post 24 may be positioned at different angles, depending uponthe style of bike desired. In the illustrative "upright" style, the postis close to vertical, at a small angle with the fork prongs as shown inexaggerated fashion in FIGS. 4 and 5. This creates an offset for thepost from the fork in the folded position, increasing the displacementcreated by the tilted hinge axis 39. When the angle of the post ischanged to produce different styles of bicycle, the angle of the hingealso can be changed to insure that the handlebar and post are located inthe folded condition in the proper position for compact folding of thebicycle.

A latch 61 for the steering post 24 operates between the two bases 41and 55, on the side of the post opposite the hinge pin 54, to hold thebases rigidly together for normal operation. The latch used in thisinvention is particularly advantageous, because it is readily accessibleto be released quickly and easily, while being unobtrusive when latchedand when unlatched, re-latches automatically as an incident to return ofthe post to its upright position, and securely and safely holds the postwhen it is latched.

As shown most clearly in FIGS. 18 to 21, the latch 61 is of theovercenter toggle type having an actuator arm 62 of channel-shapedcross-section that is pivoted at its lower end on a pin 63 securedbetween two wings 64 on the hinge base 55, opposite the hinge pin 54, asecond arm 65 in the form of a connecting rod that is pivotallyconnected at one end to the free upper end of the actuator arm by a pin67 and at the other end to the base plate 41 of the post 24, on a pin 68between two wings 69 thereon normally overlying the wings 64, so thatthe pin 68 overlies the pin 63 and the second arm 65 generally parallelsthe actuator arm 62 and lies within the channel therein in the latchedposition. The upper pin 67 at the "knee" of the toggle joint isovercenter relative to the lower pivot pins, to the right as viewed inFIG. 20, to lock the latch closed. The opposite end portions of thesecond arm 65 are oppositely threaded fittings into which the connectingrod portion is threaded, so that the length of this arm is readilyadjustable. A torsion spring 70 is coiled around the pin 63 with onefree end portion 70a against the actuator arm and the other free end 70bagainst the hinge base 55 to urge the actuator arm clockwise (FIG. 20)and produce a self-locking action upon return of the post to the uprightposition, and also to resist inadvertent unlatching.

It will be noted that in the upright position of the actuator arm 62along the post, the actuator is completely unobtrusive and out of theway. At the same time, it is readily accessible to unlatch the post 24for folding, and release the post after a simple and quick flip of theactuator arm 62 away from the post, allowing it to be moved to theposition shown in FIG. 19, but preferably after reversal of the wheel.In the unlatched condition, the latch has no loose components to flop orrattle, and has a low profile that adds little or nothing to the overallfolded size of the bicycle. Upon return of the post to the uprightposition in FIGS. 18 and 20, the latch re-latches with a snap action,and holds the post securely in place.

Another space-saving feature is the vertical compactness of the wheelsupport 23 and the steering bearing 40 therein, which is of the "ballbearing" type that conventionally has been made as a "headtube" that isseveral inches long in order to sustain the torque forces to which thebearing is subjected in operation of the bicycle. It has been found thatsuch length is unnecessary if, instead, the bearing is made considerablywider and flater, apparently because the increased lateral separation ofthe races of the bearing and the proportionate increase in the number ofballs therein produce similar torque and superior thrust-carryingcapabilities, as compared to the greater longitudinal separation of theraces in conventional bicycles.

Shown in FIGS. 22 and 24 are alternative bearings, the basic bearing ofFIG. 22 having parts indicated by the same reference numbers used in thepreceding drawings, and being the presently preferred embodiment. Thisbearing has two series of balls 71 that roll in raceways defined betweenan internal flange 72 in the arcuate sidewall 23a of the wheel mount, anupper bearing ring 73 that abuts against the underside of the hinge base55, and a lower bearing ring 74 that abuts the upper end or crown 22 ofthe wheel support. Herein, the opposite sides of the internal flange 72are formed with oppositely opening grooves constituting the lower raceof the upper series of balls 71 and the upper race of the lower series,and the upper ring has a grooved lower end which forms the upper racefor the upper series of balls. The lower race for the lower series ofballs is a V-groove in the lower ring 74. The upper bearing ring isinternally threaded and for fine adjustment of the entire bearingassembly is held on an externally threaded coupling 76 that projectsupwardly from crown 22 of the wheel support 23 and a machine screw 77extends downwardly through a hole 78 in the hinge base and is threadedinto the coupling 75 and the crown 22 of the fork, thus clamping thebearing elements together and joining the steering post 24 to the wheelsupport through the hinge and the bearing.

Also shown in FIGS. 22 and 23 are means for maintaining the generalangular alignment of the handlebar post 24 with the fork, despiteangular displacement which may result from a crash or abusive handling.While this may take various forms, one suitable form includes a tubularretainer 79 (see FIG. 23), with locating lugs 80 spaced around its upperend, attached to the lower portion of the bearing assembly. Herein, theretainer is brazed into the coupling rib 75, with the lugs 80 projectingupwardly through a hole 81 in the bottom wall of the hinge base 55.

Fitted into the hinge base 55, which has a downwardly tapering insidewall 82, is a retainer cup 83 that has a downwardly tapering outsidewall 84 sized to be wedged into the hinge base. This cup has arcuateslots 85 in its bottom wall through which the lugs 80 project, to form alimiting connection between the cup and the retainer, and thus with thewheel supporting fork. The cup 83 produces a strong frictional forceresisting misalignment. Realignment is achieved by first loosening thescrew 77, then aligning the parts, and then re-tightening the screw 77.This is but one of the wheel-alignment arrangements that may be used.

The alternative bearing shown in FIG. 24 is similar in construction, andcorresponding parts are shown with corresponding primed referencenumbers. This bearing has one set of balls 71' that ride in a racewayformed between an internal V-groove in the band 23a' of the wheel mount23', and two external beveled edges of an upper bearing ring 73' a lowerbearing ring 74'. In other respects, this bearing is the same as that inFIG. 22.

With each of these bearings, the total height is about one-quarter thewidth. For example, the bearing may be less than two centimeters inheight, FIGS. 22 and 24 being shown in approximately full scale for thepreferred embodiment of the bicycle.

The folding frame 13 is made in two sections that are generally flatsided and flat topped, and are pivotally joined together by a mid-framehinge 88 defining an upright axis 89 that is midway between the frontand rear axles 21 and 18 when the front wheel is positioned for foldingof the frame, the actual position being different when wheel reversal isto be used during folding, as here, and when it is not to be used. Thispermits the two sections to swing into a side-by-side folded conditionwith the two axles in end-to-end relation, with the two wheels 11 and 12side-by-side, and with the folded handlebar 25 compactly disposedbetween the wheels.

The preferred frame construction for combined lightness and strength isa framework of welded tubular struts, herein in an open-frame or abox-like configuration in which both the front section and the rearsection are of generally triangular shape, the flat bases of thetriangular sections being butted together at the mid-frame hinge 88.This so-called "diamond" frame configuration, producing an overallparallelogram-like frame shape, is generally similar to that used inconventional non-folding bicycles, but has not been usable in mostfolding bicycles.

As shown in FIGS. 1 and 2, the front frame section has a flat upper sidegenerally in the position of a conventional "top tube", formed by twohorizontal struts 90 with forward end portions converging toward andfastened to a rearward extension 23b of the wheel mount 23, a downwardlyand rearwardly inclined underside, generally in the position of aconventional "down tube", formed by two inclined struts 91, also withconverging forward end portions fastened to the wheel mount, and anupright rear side formed by two vertical struts, one forming themid-frame hinge 88 and the other, numbered 92, being welded at its endsto the upper and lower struts 90 and 91 on one side of the frame. Twohorizontal cross-struts 93 complete the rear side as a rectangle. Itwill be seen that both the upper side and the underside can be formed bya single "top tube" and a single "down tube" if desired, withoutdetracting from the structural integrity and if a front storage space(to be described) is not desired.

The rear frame section (apart from the rack 26) has a downwardlyinclined upper side that is formed by two elongated struts 94 thatextend rearwardly to the rear axle 18, generally in the position ofconventional "seat stays", each being connected to the seat assembly andto the rack 26 at its upper end. The rear frame section has a generallyhorizontal lower side formed by two struts 95 extending forwardly andslightly downwardly from the rear axle, generally in the position ofconventional "chain stays", and an upright front side formed by twovertical struts 97 that are welded at their upper and lower ends to theforward ends of the rack, which herein is a U-shaped tubular strutreinforced by two cross-struts 26a. Two short horizontal cross-struts 98complete the front side of the rear frame section as a rectangle, and athird short cross-strut 99 (FIG. 2) preferably extends between the twoupper struts 94 to provide a mount for the rear brake 30. The oppositeends of the rear axle 18 are received in and bolted to two mounts 100forming the rear wheel "drop outs" , and constituting the rear end ofthe rear frame section. The rear end of the rack is supported by twobraces 101 joined at their lower ends to the rear mounts 100. The endsof the axle preferably have very short laterally projecting ends, andmay be covered to further reduce the number of protruding parts.

As can be seen in FIGS. 1 and 2, the uppermost parts of the front andrear frame sections lie generally along an imaginary horizontalreference line extending from the front wheel mount to the rear of thebicycle, producing a flat-topped, low-profile frame that also isrelatively flat sided and without objectionable protruding parts. Thisframe is only slightly higher than the small-diameter wheels, and is ofapproximately the same width as the wheels and their supports, includingtheir axles, for optimum compactness in the folded condition, as will beseen.

To form the mid-frame hinge 88, a pivot sleeve 102 (see FIGS. 1 and 3)is mounted in parallel alongside one of the upright struts 97 of therear frame section, herein the right-hand strut as viewed in FIG. 3, anda hinge pin 103, shown in broken lines, is fitted rotatably in thesleeve and captured at its ends in two coaxial caps 104. The sleeve andthe caps, joined by the hinge pin 103, make up one vertical strut of thefront frame section, on the side of the frame opposite the sprocket 15,as well as forming the mid-frame hinge. For optimum folding, the hingesleeve 102 preferably is offset slightly rearwardly and outwardly aroundthe strut 97 of the rear section, about sixty degrees away fromfront-to-rear alignment.

A mid-frame latch 105 is located on the other side of the frame 13 fromthe hinge 88, and preferably is an overcenter toggle latch similar tothe steering post hinge latch 61 in construction and operation. For thispurpose, an actuator arm 107 (FIGS. 3, 29 and 30 to 32) is pivoted atone of its ends on the underside of the front frame section, herein by aheaded pin 108 (FIG. 31) projecting downwardly out of the adjacentvertical strut 92 forming the rear side of the front frame section. Thefree end of this actuator arm, which preferably is of channel-shapedcross-section like the arm 62, is pivotally connected by a pin 109 toone end of an adjustable second arm 110, and the other end of thissecond arm is pivoted on a pin 11 projecting downward from the lowercross-strut 98 of the rear section. Thus, when the frame is unfolded andthe latch 105 is closed (FIGS. 1 and 29), the two pivot pins 108 and 111are side by side, and the two latch arms extend rearwardly in overcenterlatched condition, as shown in FIG. 29. When the actuator arm 107 isswung inwardly, the latch opens to permit the frame sections to befolded to the position shown in FIGS. 3 and 32, in which the arms 107and 110 are generally in line and connected across the mid-frame of thebicycle.

For double latching at vertically spaced points, the latch pin 108extends through the strut 92 and projects from the upper end, the pin108 being rotatably supported by bushings 112 (see FIG. 31), and aduplicate latch 105' is formed on top of the frame, correspondingelements of this latch being indicated by the same reference numbers inthe drawings. If desired, the top latch may be eliminated or simplifiedbecause of the concentration of forces during riding at the lower latch.With or without the upper latch, the lower latch very securely holds theframe latched, with the actuator arm 107 unobtrusively located in afront-to-rear position beneath the frame, yet easily accessible to beflipped open to release the frame. The latch remains unobtrusive whenthe frame is folded, as shown in FIG. 3, to permit use of the pivotsleeve 102 and the adjacent strut 97 as a carrying handle.

To hold the folded frame sections firmly together in the foldedcondition a simple catch 194 (FIG. 1) is mounted on one of the sectionsto engage a strike 195 on the other section. Herein, the catch 194 is agenerally U-shaped strip of spring metal forming a constricted openingthat is mounted on the rear rack 26 above the rear wheel 12, and thestrike 195 is arrowhead-shaped and is attached to the post 24 inposition to enter and be held releasably by the catch. These elementstie the folded package together in an easily handled package.

Although the folded bicycle 10 may be left on its wheels in a generallyhorizontal position, or laid on its side for storage, the frequentlypreferred position for storage is "on end", with the mid-frame endsfacing up, as shown in FIGS. 3 and 8, with the mid-frame hinge 88 andthe adjacent strut 97 conveniently positioned to serve as a carryinghandle, as shown in FIG. 3. It will be seen that the rear ends 27a and28a of the fenders are extended downwardly and outwardly to lie alonghorizontal lines that are tangent to the wheels in this uprightposition, to provide a four-point stance for the folded bicycle. Iffront wheel reversal is not used during folding, either a three-pointstance is used, or the front end of the front fender 27 is positioned toprovide the fourth point.

The collapsible seat assembly 14 is integrated compactly into the rearframe section in a manner that not only securely supports a seat orsaddle 113 but also reinforces the frame 13. As can be seen in FIGS. 1and 2, the seat assembly herein comprises three telescoping tubular seatpost sections 114, 115 and 116, the first forming the base of the postand the other two constituting extension sections for elevating the seat113 to a desired height. For non-rotational support, the sections are ofnon-circular cross-sectional shape, herein square, and a quick-releaselatch 117 is provided at the upper end of the intermediate section 115and on the lower section 114 for holding the next upper section securelyin the extended position, which preferably is determined by anadjustable limiting cable (not shown) similar to the steering post cable49, anchored at its lower end in the base section 114 and at its upperend to the upper section 116. Reference is made to the aforesaid patentfor details regarding such a cable.

The lower latch 117, as shown in detail in FIGS. 5, 25 to 27, is mountedon one side of the lower post section 114, preferably well below theupper end thereof, and comprises a latch arm 118 that is pivotallymounted at one end on a pin 119 that is supported between the twoparallel sides 120 of a U-shaped channel forming the body of the latch.The channel is fastened to the side of the lower post section with thepivot pin 119 parallel to the longitudinal axis of the post.

The latch arm 118, which preferably is a flat, rectangular plate fittingloosely between the two sides 120 of the channel, has a latch lug 121 onits inner side for projecting through opening 122 and 123 in the channeland the lower post section 114 and into an aligned opening 124 in theintermediate post section, thereby to latch the two sections againstrelative sliding movement. The latch lug 121 fits relatively snuglybetween the upper and lower walls of the openings 122, 123 and 124, fora minimum of play in the post.

To urge the latch arm 118 yieldably toward the latched position (FIG.26), a spring 125 is coiled around the pin 119 and anchored at one end126 in the channel, with its other end 127 extending along the outerside of the latch arm. The free end portion 128 of the latch armprojects slightly beyond the post to provide an easily accessible gripfor use in disengaging the latch. The upper latch 117 is the same as thelower latch, so the details are not repeated in this disclosure.

For adjustability of the length of the seat post, at least one of theinner telescoping post sections 115 or 116 should have a series oflongitudinally spaced holes 124 for alignment with the outer holes 122and 123 in different telescoped positions of the seat post. Herein, theholes 124 are provided in both sections 115 and 116, and are shown bybroken lines in the intermediate section 115. The length of theseat-height cable can be set with the latch engaged in a hole 124producing the desired height, after which the cable will limit theextension of the seat post to that height while the latches areunlatched, contributing to quick unfolding of the bicycle. Similar latchholes are provided in the intermediate and upper sections for engagementwith the latch lugs 121 when the seat post is collapsed, so as to holdthe post securely in the collapsed condition.

The position of the base section 114 in the frame 13 determines theangle of the seat post relative to vertical, this angle beingconventional and approximately fifteen degrees as shown in the drawings.The lower end of the base section is welded between the two lower struts95 and to the lower cross-strut 98, and the upper end portion is weldedbetween the two upper struts 94. Preferably, a transverse mountingsleeve 130 for the sprocket/pedal assembly also is welded to the basesection, having a notch 130a for interfitting with the base sectionacross its front side, and also is welded to the front struts 97, thustying the seat post and all of the other elements together.

As shown herein, the square tubular sections are oriented with a corneror edge 131 facing forward, as shown most clearly in FIGS. 25 and 26.This provides a nesting effect under the downward and rearward forceproduced by the weight of a person on the seat, for a firmer fit andless "play" in the seat assembly. The latches 117 may be located on anyside, but preferably are on one of the front sides with the grippingedges 128 overhanging the front edge 131.

The sprocket/pedal assembly of the preferred embodiment comprises abasically conventional drive sprocket 15 or chainwheel that is rotatablymounted on the rear frame section by means of an axle 132 that isjournaled in the transverse sprocket sleeve 130 in anti-frictionbearings 133 (FIG. 28), and two foldable pedal cranks 134 and 135 thatare pivotally mounted on connectors 137 on the opposite ends of thecrankshaft 132 for swinging into out-of-the-way positions tucked intothe frame 13.

As shown in FIGS. 25, 28 and 29, the drive sprocket 15 comprises arelatively large sprocket ring 138 with a series of sprocket teetharound its outer periphery, and a central body or "spider" 139 withangularly spaced radial arms that are fastened to the ring by screws140. The sprocket body is fitted non-rotatably onto a tapered endportion 141 (FIG. 28) of the crankshaft and clamped against a shoulderthereon by a bolt 142 that is threaded into the end of the shaft throughone of the connectors 137, the other connector being similarly fastenedby a bolt 143 to a tapered end portion 144 on the opposite end of thecrankshaft, both of these tapered ends preferably being splined orotherwise made non-circular for a non-rotational fit. End rings 145 arethreaded into the opposite ends of the sleeve 130 to retain the bearings133 therein, with the crankshaft projecting outwardly through each ring.

This is an illustrative mounting arrangement for the connectors, whichcould be replaced by other conventional crank mounting arrangements thatare well known in the trade.

Each of the pedal cranks 134 and 135 is an elongated arm carrying arotatable pedal 19 on a headed shaft 147 adjacent its free, radiallyouter end, the pedals being horizontal in the normal operating positionsof the cranks. The radially inner end portion 148 of each crank overliesone end of the crankshaft 132 and the connector 137 thereon, and isdrivingly coupled to the crankshaft through the connector in the normaloperating condition of the assembly. This driving connection is formedby a pivot pin 149, opposed driving abutments 150 and 151 on the crankand on the connectors, respectively, and a quick-release latch 152,which normally maintains the driving abutments in opposed and coupledrelation.

As can be best seen in FIGS. 25, 28 and 29, the inner end portion 148 ofeach crank 134, 135 is thickened and slotted on its laterally inner sideto form two spaced driving lugs with spaced parallel, generally radiallydisposed inner sides forming the abutments 150, which are disposed onopposite sides of the associated connector 137, the latter being a shortbar having flat and parallel, generally radially disposed opposite sidesconstituting the abutments 151, the assembly thus having male connectorson the crankshaft engageable with female connectors on the cranks,providing relatively large driving surfaces with relatively smalllateral dimensions and overall lateral compactness resulting from use ofthe same lateral space for the mounting of the connectors and thedriving surfaces. The inner end portions of the cranks extend beyond thesprocket axis 153 and are pivoted on the connectors, on the side of thesprocket axis opposite the pedals, by the pivot pins 149 (FIG. 28) whichare fastened in the driving lugs and extend through the connectors inplanes that are perpendicular to the sprocket axis.

The connectors have laterally inner faces that lie against the sprocketon one side and adjacent a shoulder on the other, and the cranks havelaterally inwardly facing locating surfaces 154 which abut against theouter sides of the connectors to determine the normal operatingpositions of the cranks. Thus, the laterally inner sides of the radiallyinner end portions 148 need not abut against the sprocket or theshoulder on the crankshaft, and may be shaped for greater compactness inthe folded positions.

To lock the cranks releasably in these operating positions, the latches152 (see FIG. 28) are positioned on the side of the sprocket axis 153opposite the pivot pins 149 and act between the cranks 134, 135 and theconnectors 137, each latch herein being in the form of a bell crankhaving one elongated actuating arm 155 extending radially outwardlyalong the crank from a pivot pin 157 supporting the latch on the crank,and a second, latching arm 158 extending laterally inwardly through apassage 159 in the crank to lie alongside an end of the associatedconnector 137. On the free inner end of the latching arm is a hook-likelatching abutment 160 having a laterally outwardly facing surface forengagement with a laterally inwardly facing latching shoulder 161 on theconnector. A coiled compression spring 162 is confined between a finger163 that is an extension of the actuator arm 155 on the opposite side ofthe pivot pin 157, and constitutes means for yieldably holding thelatches in the latched condition shown in FIG. 28, with the crankssecurely engaged with the connectors 137.

When an actuator arm 155 is swung laterally outwardly against the forceof its spring 162, however, the latching abutment 160 is disengaged fromthe latching shoulder 161 to permit the associated crank 134 or 135 tobe swung away from the normal position, counter-clockwise as viewed inFIG. 28, to the folded position shown in broken lines in FIG. 28. Theactuator arms 155 are curved as shown in FIG. 25 to generally follow theangles of the cranks, but overhang slightly along one edge to facilitategrasping of the latches to release them and fold the cranks in a quickand simple operation.

The pedal cranks 134 and 135 are specially shaped to provide for morecompact folding than would be possible with conventional straightcranks. First, the crank 135 on the sprocket side of the frame, on theright in FIG. 28, is inclined laterally outwardly from its inner endportion 148, to space the pedal from the sprocket for normal operatingclearance. When this crank is folded, however, its folded inner side(164 in FIG. 28) is substantially perpendicular to the sprocket axis153, and the crank as a whole is closer to the frame. The "hump" 165 onthe radially inner end portion of the crank is the laterally outermostpart of the pedal/sprocket assembly, and is only slightly beyond theconnector 137 on the end of the crankshaft 132. The slight relief shownbetween the unfolded crank and the sprocket 15 slightly reduces theheight of the hump 165.

On the other side, the radially outer end portion of the crank 134 isoffset laterally outwardly from its inner end portion 148, as indicatedat 167 (FIG. 28), to clear the laterally offset mid-frame hinge 88 onthat side. When this crank is folded, it also is closer as a whole tothe frame, with a relieved hump 168 that is the laterally outermostpart.

Another feature of the special cranks is an angular offset of the outerend portion of each crank from a true radial position, each crank beingbent at an angle of the order of thirty to forty degrees with theradially disposed inner end portion 148, for the outer approximatelythree-quarters of its effective length, as shown in FIGS. 2, 25 and 29.These angular offsets are to the rear, and make it possible to fold bothcranks into positions in which the now-inwardly extending pedals 19 willtuck conveniently into the rear frame section, while maintaining anormal operating relationship between the pedals when the cranks areunfolded. It will be evident that, with the angular offsets of the innerend portions, the connectors 137 are not angularly aligned with eachother, but rather are aligned with the inner end portions of theirrespective cranks.

FIG. 25 illustrates in full lines the preferred starting position forfolding the pedals 19, with the sprocket-side pedal lowered and theother pedal raised. When the raised pedal is unlatched and swungdownwardly, the angular offset shifts the pedal rearwardly, away fromthe underside of the sprocket, to the position shown in broken lines,under the frame strut 19 and immediately in front of the rear wheel. Theposition of the strut and the length of the folded crank are correlatedto position the pedal for latching engagement with the strut, as shownin FIG. 25, and as permitted by inherent flexibility of the parts. It isto be noted that the over-center position of the crank pivot pin 149actually increases the folded lengths of the crank.

Similarly, when the lowered sprocket-side crank 135 is unlatched andswung upwardly to the folded position shown in broken lines in FIG. 29,the angular offset in the crank shifts its pedal 19 rearwardly as well,into a tucked position behind the seat post base section 114 andoverlying the rack 26. Again, the position of the strut forming the rackand the length of the folded crank are correlated to provide forlatching of the pedal over the strut, as permitted by the resilientflexibility of the parts.

DETAILED DESCRIPTION OF THE SECOND EMBODIMENT (FIGS. 33 TO 35)

Shown in FIGS. 33 through 35 is a modified embodiment of the bicycle 10with detailed features in addition to the features in the firstembodiment. In view of the overall similarity of the basic elements ofboth embodiments, corresponding parts that may be the same are indicatedby the same reference numbers used in connection with the firstembodiment.

The first optional feature, shown in FIG. 30 is the formation of thefront frame section as a box-like enclosure, indicated generally by thereference number 170, that may be of the same triangular shape as thefront frame section of the first embodiment, and indeed may be formedsimply by covering that front frame section with sheet material such asfiberglass or sheet metal. As shown herein, the front section 170 ismade up of two triangular side panels 171, a generally rectangular toppanel 172 forming a front deck with a central access door 173 supportedby a piano hinge 174 on one longitudinal side, and a generallyrectangular bottom panel 175 closing the underside of the box. The rearside preferably is substantially closed by a rear panel 177, which maybe a wrap-around extension of one side panel 171.

As shown in FIGS. 34 and 35, the struts of the front frame section ofthe first embodiment are within the enclosure 170, which is simplyoverlaid on the triangular framework. At the front end, the enclosureencases the rearward extension of the front wheel mount 23, and blendssmoothly with the arcuate band 23a forming the front wheel bearing cage.

With the use of sufficiently strong material for the enclosure 170, theinternal framework may be eliminated, and the wheel mount 23 may bejoined to the front end of the enclosure, and the hinge 88 joined to onerear corner thereof, with the latch 105 mounted along the opposite rearcorner. In all other respects, the basic components of the bicycle ofthe second embodiment may be the same as in the first embodiment.

The second optional feature illustrated in FIGS. 33 to 35 is a specialflexible seat-bracing cable 178 that is usable with the bicycles of anyof the embodiments to reinforce the seat structure 14 for unusuallyheavy riders, or to permit the use of lighter materials for the seatpost sections 114, 115 and 116. This cable is attached at one end to thetop of the intermediate section 115, and extends downwardly andforwardly to the front end portion of the frame 13. While it may besimply anchored to the frame (on the front wheel mount 13, for example),herein it extends into the front section through a hole 179, and thenback through the enclosure 170 to a suitable anchor. To provide fortaking up of slack in the cable 178 to some extent upon folding of theframe 13, and also to reinforce the mid-frame hinge latch 105, the cable178 preferably is wrapped around the two lower cross struts 93 and 98 ofthe two frame sections, near the side of the frame opposite the hinge88, and anchored on the rear section by a screw 180 that is set into theunderside of one of the struts 95.

Accordingly, the cable holds the seat assembly 14 against rearwarddeflection under the weight of a heavy cyclist on the bicycle, andtension in the cable 178 resulting from the rearward force on the seatassembly is applied to the adjacent cross-struts 93 and 98 of the framesections to bind them together, opposing the tendency of the weight onthe center of hinged frame to spread them apart. Then, when the bicycleis being folded, the spreading of these two cross-struts during foldingof the frame takes up some of the slack in the cable, to reduce its freelength in the folded package.

DETAILED DESCRIPTION OF THE THIRD EMBODIMENT (FIGS. 36 TO 38)

An additional optional feature illustrated in FIGS. 36 through 38 is a"shopping cart" mode of the invention, in which the partially foldedfront and rear frame sections are held with the front and rear wheels 11and 12 parallel and spaced apart, and an auxiliary wheel assembly 181 isattached to the mid-frame area to provide an extra wheel and form athree-wheeled cart. This feature makes it possible to use the bicycle tocarry groceries of merchandise while shopping and then to convert backto the bicycle mode to carry the groceries or merchandise home. It alsocan be used with the fully folded bicycle, as a three-wheeled supportpermitting easy rolling rather than carrying, using the partiallyextended seat as a handle. Again, apart from the optional features, thisembodiment may utilize the same basic components as the otherembodiments, so corresponding parts are indicated by the same referencenumbers, and duplicative drawing details are not repeated in thesefigures.

More specifically, a flexible elastic strap 182 (see FIG. 36) isprovided to tie the two sections together in a partially foldedcondition with the wheels 11 and 12 parallel, the clip having hooks 183at its ends for hooking around one side strut of the rack 26 when thestrap has been looped around the front post 24 above the wheel mount 23.The detent strap 60 (FIGS. 16 and 17) has a second detent notch 184engageable with the detent pin 59 o hold the steering assembly in theproper angular position for this mode.

It can be seen in FIGS. 36 and 38 that the pedal cranks 134 and 135remain in their normal operating positions in this mode, with the crank134 extending downwardly between the two partially folded frame sectionsand serving as a limiting stop preventing folding of the sections intoside-by-side relation. The strap 182 pulls the two sections toward eachother, and holds the front section snugly against the pedal crank 134with the front wheel in the proper attitude, as determined by the detentpin 59 in the notch 184.

The auxiliary wheel assembly 181 comprises a small castor-type wheel 185that is swivelly mounted on the lower end of a body 187 that ispivotally mounted at its upper end on a cross pin 188 spanning the twofront struts 97 of the rear frame section, the body having a notch 189(FIG. 37) in its rear side for receiving the lower cross-strut 98 of therear frame section when the wheel is lowered, and releasing the wheelassembly to swing upwardly into a storage position (broken lines in FIG.37) when not in use. A recess 190 in the front side of the wheel body187 provides storage clearance for the sprocket sleeve 130. This entireassembly can be of molded plastic construction, weighing somewhere inthe vicinity of one pound, and thus is light and relatively inexpensive.

When the bicycle has been folded to the shopping cart mode with thewheel assembly 181 lowered, the rear carrying rack 26 is available tocarry groceries or other merchandise, possibly in a container that canbe tied down to the rack. The handlebar 25 and front post 24 preferablyremain in the unfolded condition, and the seat assembly is at leastpartially extended. When one of the seat post sections remains extendedand the other collapsed, the seat 113 is at a convenient height to serveas a pushing or pulling handle for the "cart".

The bracing cable 178 may be provided for this embodiment, or may beomitted, depending upon the needs of the particular cyclist. It isomitted from FIGS. 36 through 38, for simplicity of illustration. Likethe bracing cable, the auxiliary wheel assembly 181 and the elasticstrap 182 may be made available as optional attachments for the basicbicycle, or omitted if a particular cyclist has no need for them, ordoes not want the added weight. For a person who uses the bicycle of theinvention in shopping, however, these optional additions willsignificantly increase the utility of the bicycle.

DETAILED DESCRIPTION OF THE FOURTH EMBODIMENT (FIGS. 39 TO 42)

Shown in FIGS. 39 to 42 is an alternative embodiment of the handlebarand steering assembly indicated generally by the reference number 200,in which the handlebar 201 is turned from the normal laterallyprojecting position as a separate additional step, rather than by thepositioning of the hinge for the steering wheel post 202. This is analternative to the preferred automatic turning of the handlebar, but isusable to accomplish the same end result, if desired. Parts of thisembodiment which may be identical to corresponding parts of thepreferred embodiment are indicated by the same reference numberspreviously used.

As in the preferred embodiment, the handlebar 201 is mounted on theupper end of a normally upright steering post 202, comprising a basesection 202a and an extension section 202b telescoped therein, thehandlebar having a central section that is secured to the upper end ofthe extension section of the post and laterally projecting opposite endportions 201a and 201b that are inclined downwardly and rearwardly in ashallow "V" configuration for relatively small front-to-reardisplacement. The lower end of the post 202 is secured to a transversebase plate 203 which overlies a hinge base 204, and is pivoted on thehinge base by a hinge pin 205 on one side of the post, and a latch 207is provided on the other side to secure the post in the uprightposition. As before, the hinge base overlies the front wheel mount 23,and the front wheel support 20, 22 extends downwardly from the frontwheel mount to support a front wheel.

In this instance, the extension section 202b and the upper end of thebase section 202a are of circular cross-section so that the handlebar201 is rotatable relative to the base section about the longitudinalaxis of the post, and means are provided for locating the extensionsection in different angular positions relative to the base section, fornormal operation and for folding. For rapid location, a detent lever 208is mounted on the outer side of the base section to extendlongitudinally thereof, being pivoted on a lug 209 on the side of thebase section, with a detent pin 210 adjacent its upper end extendinginto the base section through a hole 211 therein, and with its lower endportion yieldably urged outwardly by a leaf spring 212 confined betweenthe lever and the base section.

Formed in the telescoping portion of the extension section is a seriesof longitudinal holes 213 which are alignable with the hole 211 in thebase section to receive the inner end portion of the detent pin 210 indifferent longitudinal positions of the extension section, foradjustment of the height of the handlebar. These holes are alignablewith the detent pin when the handlebar is in the normal operatingposition.

Spaced ninety degrees around the extension section 202b from the holes213 is one hole 214 which is alignable with the detent pin 210 when theextension section is fully collapsed and the handlebar is turned ninetydegrees to its folding position, shown in broken lines in FIG. 39. Thus,this hole cooperates with the detent lever 208 and the pin 210 to latchthe handlebar in the folding position.

More secure latching of the handlebar 201 is accomplished by aquick-operating clamp 215 that is mounted on the upper end of the basesection 202a to constrict the latter around the extension section 202b,the upper end portion of the base section being longitudinally split, asshown at 217, to render it sufficiently flexible for clamping. Thisclamp is capable of developing a high clamping force with a simplemotion, and also is designed to remain unobtrusive despite variationsthat may occur in use.

More specifically, the clamp 215 comprises a split collar 218 thatencircles the flexible upper end portion of the base section 202a, ascrew 219 extending through a hole 220 in one end of the collar and isthreaded into a hole 221 at the other end, and a lever 222 fortightening the screw to draw the two ends of the collar together. Thescrew has a tapered and splined head 223 which is received in acorrespondingly shaped socket 224 in the lever, and a screw fastener 225secures the lever on the head in different angular positions. Thispermits adjustment of the lever to insure that it is in an unobtrusiveposition alongside the post when it is clamped.

As can be seen in FIGS. 39 and 40, the hinge pin 205 in this embodimentis disposed along one lateral side of the post 202, rather than beinginclined, so as to swing the post directly over to the side, without anyturning motion, turning of the handlebar 201 being a separate operation.The hinge pin is positioned relative to the wheel support 20, 22 to foldthe post into a position alongside the depending prong 20 of the fork ina manner similar to that shown in FIG. 3. The amount of separation ofthe post from the fork prong will depend unon the normal operating angleof the post relative to the wheel support. In all other respects, thebicycle of this embodiment may be the same as in the previouslydescribed embodiments.

SUMMARY OF FOLDING AND OPERATION

Specific reference is made to FIGS. 4 through 9, which represent indiagrammatic form the basic functional components of the bicycle in allof the various embodiments and the steps in folding a bicycle inaccordance with the present invention. FIG. 4 shows the bicycle in anormal operating condition with both the seat assembly and the handlebarand steering assembly extended, the latter including partial extensionof the upper post section 24b to a height somewhat above racing height.The pedals 19 are positioned as shown, with the sprocket-side pedaldown.

As a preferred first step (FIG. 5), the clamp 42 is released to collapsethe upper post section 24b and then reclamped, and the front wheel isreversed to the preferred folding position. Also, the two pedal cranksare released in succession, each by flipping its latch 152 and swingingthe crank to a generally oppositely extending position, and engaging itwith a frame member, as shown in other drawings.

Then, the latch 61 is released and the steering post 24 is folded over(FIG. 6), and the latches 117 are released in succession and the seatstructure is collapsed. The only remaining step is to release themid-frame latch 105, and to swing the two frame sections intoside-by-side relation (FIG. 7), with the two axles end to end. The catchelements 194 and 195 are engaged as the sections come together, andthereafter latch the sections releasably together, for tightness of thefolded package. It will be noted that the brake and gear-shift cables34, 35 and 38 are positioned to lie compactly within the folded frame,and to be taken up to some extent, and neatly held, in the folded frame.

FIG. 8 illustrates a standing position of the folded package, which usesthe rear ends 27a, 28a of the fenders, with the wheels, to providefour-point support, with the mid-frame hinge 88 and the adjacent strut97 positioned to serve as a carrying handle. FIG. 9 shows a convenientrolling condition of the folded package, in which one section 116 of theseat post is extended to position the seat 113 to serve as a convenienttowing or pushing handle.

Unfolding and set-up are accomplished by reversing the folding steps,first unfolding the frame and latching it open with the latch 105, thenraising and latching the seat assembly and the handlebar post, returningthe front wheel to its forward position, and swinging the pedal cranksback to their normal positions. Each of the cranks relatchesautomatically as an incident to its return to the normal position, as dothe posts supporting the handlebar and the seat. Then, if furtherextension of the handlebar is desired, the clamp 42 is loosened topermit extension of the upper section, and is tightened to clamp thesection in place.

If use in the shopping cart mode of FIGS. 36 to 38 is desired, the frontwheel is turned to the partially reversed position for the cart mode,and the mid-frame hinge 105 is opened, with the pedals remainingunfolded and the handlebar up, and the elastic tie 182 is applied tohold the frame sections with the wheels parallel. Then the castorassembly is lowered (or installed, if it is not permanently installed)and the seat is set to the proper height to serve as a handle. To returnto the bicycle mode, the castor is raised, the elastic tie is removed,and the frame and the front wheel are returned to their normalpositions.

CONCLUSION

From the foregoing detailed description, it should be apparent that thepresent invention provides a unique foldable bicycle or other vehicleembodying several improvements which are effective separately and incombination to produce optimum results in terms of speed and convenienceof folding and unfolding, and of compactness and regularity of shape ofthe folded package, in which the flat-topped, low-profile frame, havinga width substantially the same as the width of the wheels and theirsupports, and is folded into a generally flat-sided compact package,without objectionable protruding parts and with the normally protrudingcomponents folded, tucked and stored tightly and securely in the frame.Moreover, the construction is capable of being mass-produced at acompetitive cost with lightweight materials, using conventionalmanufacturing technology, and has operating characteristics that comparevery favorably with other bicycles, being adaptible to different sizerequirements, different riding styles, and different drive mechanisms tosuit the needs and preferences of different cyclists.

It also will be evident that, while the presently preferred embodimentshave been shown in the drawings and described in detail, variousmodifications, changes and adaptations, including detailed designchanges and additions, will become apparent to those skilled in the artand may be made without departing from the spirit and scope of theinvention.

I claim as my invention:
 1. In a foldable and portable bicycle, thecombination of:first and second members that normally are disposed inside-by-side relation in a normal operating position and are swingableapart about a hinge between said members defining a hinge axis along oneside; and a latch for holding said members releasably in said normaloperating position, comprising an actuator arm, a first pivot spacedfrom and parallel to said hinge axis between one end of said actuatorarm and said first member, a second arm lying alongside said actuatorarm, a second pivot parallel to said hinge axis overlying said firstpivot and connecting one end of said second arm to said second member,and a pivotal connection between the free ends of said arms, saidpivotal connection being movable in one direction relative to saidpivots into an overcenter latched position, and in the oppositedirection relative to said pivots to an unlatched position.
 2. Afoldable and portable bicycle as defined in claim 1 in which saidactuator arm is channel shaped and said second arm lies within theactuator arm in the latched position.
 3. A foldable and portable bicycleas defined in claim 2 in which said second arm has reversely threadedconnections at its ends for selective adjustment of its effectivelength.
 4. A foldable and portable bicycle as defined in claim 1 inwhich said first member is a hinge base with said hinge axis along oneof its sides, and said second member is a base plate for a steering postand being swingable upwardly when unlatched, said arms extendingupwardly from said members to be alongside the steering post in thelatched condition, and being swingable away from the post to theunlatched position to permit upward swinging of said base plate, andbeing extended across said hinge base as the base plate is swung awayfrom the hinge base.
 5. A foldable and portable bicycle as defined inclaim 1 in which said first member as an upright end of a first framesection and said second member is an upright end of a second framesection and is swingable away from said first frame section as the frameis folded, said arms extending longitudinally along one of said framesections in said latched condition and being movable laterally to theunlatched position, and being extended across said ends as the end ofthe second section swings away from the end of the first section.